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By agglomeration in a high speed mixer spherical granules having a desired granule size distribution are obtained by supplying the agglomeration liquid by means of an atomizer wheel axially positioned in the high speed mixer and by controlling the quantity and evaporation of said liquid in considera

By agglomeration in a high speed mixer spherical granules having a desired granule size distribution are obtained by supplying the agglomeration liquid by means of an atomizer wheel axially positioned in the high speed mixer and by controlling the quantity and evaporation of said liquid in consideration of the changes occurring with respect to water binding ability of the agglomerates during compaction. An apparatus for carrying out the method includes a mixer bowl with an impeller on a central shaft through the bottom of the bowl and an atomizer with an atomizer wheel with its shaft in alignment with the shaft of the impeller.

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A process for agglomerating a powdery material to obtain spherical granules of a desired narrow granule size distribution with a low intragranular porosity in a high speed mixer having an internal coating which substantially prevents the adhesion thereto of the powdery materials to be agglomerated a

A process for agglomerating a powdery material to obtain spherical granules of a desired narrow granule size distribution with a low intragranular porosity in a high speed mixer having an internal coating which substantially prevents the adhesion thereto of the powdery materials to be agglomerated and the auxiliary substances required for the agglomeration comprising the following steps: (i) introducing into the high speed mixer a powder to be agglomerated and, in a first phase, mechanical agitating the power at such a low level that no considerable agglomeration or compaction of the powder takes place and no substantial increase in temperature of the powder occurs, (ii) distributing in the first phase a liquid uniformly on the powder by atomization of the liquid with an atomizer wheel axially positioned in the mixer, the liquid being a solution of a binder or a solvent for a binder present in the powder, and (iii) adjusting the quantity of liquid to be atomized on the powder to be larger than the quantity sufficient to saturate the powder after compaction, but smaller than the amount required to saturate the powder prior to compaction, (iv) effecting compacting in a subsequent phase by using a substantially stronger mechanical agitation than that practiced in the first phase and at an increased temperature, and (v) simultaneously ensuring an evaporation of the applied liquid or components thereof by using drying gas or vacuum in unison with the decreasing liquid binding capacity of the powder during compaction, thereby completely preventing a higher liquid content in the powder than the one corresponding to saturation.